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The purpose of this paper is to investigate the equivalent control authority of the conventional and circulation control (CC) wing of the aircraft and assess the energy expenditure and aerodynamic efficiency of the CC wing.

Four target cases with different flap deflection angles θ are set in advance for the conventional wing, and then a series of cases with different jet momentum coefficients Cμ are set for the CC wing. The lift, drag and momentum coefficient curves of the CC wing are compared to those of the four conventional wing cases. The curves with the best agreement are selected to establish the corresponding relation between θ and Cμ. The energy expenditure of the CC system is analyzed. The concept of equivalent lift-to-drag ratio for the CC wing is introduced to compare the aerodynamic efficiency with the conventional wing

The control authority of the conventional wing at θ = 0º, 10º, 20º, 30º are equivalent to the control authority of the CC wing with Cµ = 0.0, 0.005, 0.009 and 0.012. The CC system is more efficient at small Cµ than large Cµ.

This study could contribute to the application of the CC system on flapless aircrafts.

The corresponding relation between θ and Cµ is established by matching the equivalent control authority between the conventional wing and CC wing.

The purpose of this paper is to study the yaw control of the flapless aircraft and investigate the equivalent control effect (ECE) and the power consumption of the pneumatic control.

The control effects of the mechanical control and the pneumatic control are calculated and the ECE curves are obtained. The power consumption of the pneumatic control is analyzed. A new pneumatic drag-type yaw control method is proposed. The mechanisms of the drag-type yaw control and the conventional thrust-type yaw control are explored. The drag-type yaw control is divided into two combined blowing forms: inner-top outer-bottom blowing and inner-bottom outer-top blowing. The differences between two kinds of the drag-type yaw control at a small angle of attack and a large angle of attack are explored.

The ECE curves of the pneumatic control are obtained. The power consumption of the drag-type yaw control is much lower than that of the thrust type. The lift coefficient of the inner-top outer-bottom blowing is higher than that of the inner-bottom outer-top blowing, but the inner-bottom outer-top blowing has higher efficiency of the yaw control at a large angle of attack.

This paper contributes to the research of the flapless aircraft.

A new pneumatic drag-type yaw control method of the flapless aircraft is proposed.

Nowadays flaps and winglets are one of the main mechanisms to increase airfoil efficiency. This study aims to investigate the power performance of vertical axis wind turbines (VAWT) that are equipped with diverse gurney flaps. This study could play a crucial role in the design of the VAWT in the future.

In this paper, the two-dimensional computational fluid dynamics simulation is used. The second-order finite volume method is used for the discretization of the governing equations.

The results show that the gurney flap enhances the power coefficient at the low range of tip speed ratio (TSR). When an angled and standard gurney flap case has the same aerodynamic performance, an angled gurney flap case has a lower hinge moment on the junction of airfoil and gurney flap which shows the structural excellence of this case. In all gurney flap cases, the power coefficient increases by an average of 20% at the TSR range of 0.6 to 1.8. The gurney flap cases do not perform well at the high TSR range and the results show a lower amount of power coefficient compare to the clean airfoil.

The angled gurney flap which has the structural advantage and is deployed to the pressure side of the airfoil improves the efficiency of VAWT at the low and medium range of TSR. This study recommends using a controllable gurney flap which could be deployed at a certain amount of TSR.

The Bell X‐1, which was the first aircraft to break the “Sound Barrier” 50 years ago, did so because of sheer determination. It was a workable, sturdy design, with a powerful rocket engine, a sufficiently skilled pilot and was backed by people of vision. That it flew successfully at Mach 1 and beyond, should have surprised no one. As Frank Whittle had said about the flight of the first British jet aircraft in 1939, “That’s what it was bloody well designed to do”.

The common property of being able to travel faster than sound does not in general confer on aircraft any other similarities of shape or form. Thus supersonic aircraft have no great body of low speed behaviour in common, consequently in order to limit the discussion the following relates to a particular type of supersonic aircraft — namely large transport aircraft of slender delta form.